Jatropha curcas is a plant of latin american origin, widely spread throughout the arid and semi-arid tropical regions of the world. Jatropha is a large genus comprising over 170 species. The commonly occurring species in india are j. Curcas, j. Glandulifera, j. Gossypifolia, j. Multifida, j. Nana, j. Panduraefolia, j. Villosa and j. Podagrica. 
Jatropha is a small tree or shrub with smooth gray bark, which exudes a whitish colored, watery, latex when cut. Normally, it grows between three and five meters in height, but can attain a height of up to eight or ten meters under favorable conditions. It is a drought resistant plant, living up to 50 years and growing on marginal lands. It has large green to pale green leaves, which are aligned alternate to sub-opposite. The leaves are three-five lobed with a spiral phyllotaxis. The petiole of the flowers ranges between 6-23 mm in length. Flowers are formed in hot seasons. In conditions where continuous growth occurs, an imbalance of pistillate or staminate flower production results in a higher number of female flowers. Fruits are produced in winter when the shrub is leafless. Each inflorescence yields a bunch of approximately 10 or more ovoid fruits.
A three, bi-valved cocci is formed after the seeds mature and the fleshy exocarp dries. The seeds become mature when the capsule changes from green to yellow, two to four months after fertilization. The blackish, thin-shelled seeds are oblong and resemble small castor seeds.
This plant has various medicinal uses especially in nutraceuticals, pharmaceutical, dermatological, and personal care products. The latex of Jatropha curcas has anticancer properties due to the presence of an alkaloid known as “jatrophine”. The tender twigs are used for cleaning teeth. The juice of the leaf is used for external application to treat piles. The roots are used as an antidote for snakebites. The bark yields a dark blue dye used for coloring cloth, fish net and lines.
The seeds are used for anthelmintic purposes. The oil of the seeds has special properties of commercial importance in that it has a very high saponification value and is extensively used for making soaps. Further, it also burns without emitting smoke. Most of these species are ornamental, except for J. curcas and J. glandulifera that are oil-yielding species (Renu Swamp, 2004. Biotechnological interventions to improve Jatropha seeds and oil quality. SAARC Oils & Fats Today, August, pp. 39-41.). The seeds contain semi-dry oil that has been found useful for medicinal and veterinary purposes (Gubitz, G. M; Mittelbach, M and Trabi, M (1999). Exploitation of the tropical oil seed plant Jatropha curcas L. Bioresource Technol. Vol. 67, pp. 73-82).
The oil content is 25-30% in the seeds and 50-60% in the kernel. The oil contains 21% saturated fatty acids and 79% unsaturated fatty acids. The Jatropha oils are linolenic acid (C18:2) and oleic acid (C18:1) which together account for up to 80% of the oil composition. Palmitic acid (C16:0) and stearic acid (C18:0) are other fatty acids present in this oil. The oil is non-edible, however it has the potential to provide a promising and commercially viable alternative to diesel oil as it has similar desirable physicochemical and performance characteristics as diesel. Of late, the plant J. curcas has attracted particular attention as a tropical energy plant. The seed oil can be used as a diesel engine fuel for it has characteristics close to those of the fossil fuel, diesel. Moreover, biodiesel extracted from Jatropha meets the European EN 14214 standards for a pure and blended automotive fuel for diesel engines due to its non-toxic and biodegradable nature. Jatropha curcas seed yields approach 6-8 MT/ha with ca 37% oil. Such yield can produce the equivalent of 2100-2800 liters of fuel oil/ha, whose energy is equivalent to 19,800-26,400 kwh/ha (Gaydou, A. M; Menet, L; Ravelojaona G and Geneste, P. (1982). Vegetable energy sources in Madagascar: ethyl alcohol and its oil seeds. Oleagineux, Vol 37 (3), pp. 135-141.).
Micropropagation can be defined as in vitro regeneration of plants from organs, tissues, cells or protoplasts using techniques like tissue culture for developing true-to type resultant plants of a selected genotype. In general, tissue from a plant, commonly known as explants, is isolated from a plant whose multiplication is desired to create a sterile tissue culture of that species in vitro. A culture is initiated from the explant. Once a culture is stabilized and growing well in vitro, multiplication of the tissue or regeneration of entire plant can be carried out. Shoots (tips, nodes or internodes) and leaf pieces are commonly used but cultures can be generated from many different tissues. Juvenile tissues generally respond best. Besides the type of explant, the chemical composition of the culture medium and the physical environment of cultures have been found to have great influence on the regeneration capacity, multiplication ratio, and growth and development of new plants in the culture system. Therefore, one needs to find the best suitable factors for individual plant species while maintaining the genotype.
Plant tissue culture is rapidly becoming a commercial method for large-scale propagation of the elite varieties and for plants difficult to propagate rapidly by conventional methods. Tissue culture is particularly useful for multiplication of plants, which are slow growing (turmeric, ginger, cardamom); cross-pollinated (coconut, teak, eucalyptus, cashew, mango and those which show wide variation in the progeny), male sterile lines (cotton, sorghum, pearl millet); and newly virus free plants by meristem culture (sugarcane, potatoes, tapioca, etc).
Known methods of Jatropha plant tissue culture have involved passage through the callus stage, which means that there is a high possibility of somaclonal variations. Earlier studies have shown either callus mediated regeneration or direct shoot bud with interspersed callus from hypocotyl, leaves, and petioles. Plant tissue regeneration through a callus stage is vulnerable to somaclonal variations and hence will not ensure true-to-type plants from elite mother plants. Thus, there remains a need for methods that allow propagation of true-to-type Jatropha plants.
There is a need to develop a protocol by which Jatropha species with desirable traits can be produced. Some of the desirable traits that a Jatropha species essentially need producing biofuel are seed yield and oil content in the Jatropha species. Other desirable traits are dwarf stem, fatty acid content, early flowering, and synchronous maturity.
Therefore, in view of the above, there is a need to develop tissue culture protocols for the rapid propagation of selected elite variety genotypes of Jatropha and for further genetic improvement of Jatropha. The present invention is directed towards the rapid propagation of selected elite variety genotypes of Jatropha and genetically improved quality of the plant, without any intermediary callus phase and also aims at producing Jatropha species with desirable traits.